The present research is a joint effort with Yale University School of Medicine to evaluate the role of the Epstein-Barr and other common viral infections in the pathogenesis of systemic lupus erythematosus, rheumatoid arthritis, and other connective tissue diseases. A battery of viral antibody tests, throat cultures for EB virus, and antinuclear antibody tests are being carried out on 48 SLE patients and 48 matched controls in order to determine whether patients with SLE harbor the EB virus and in order to determine the relationship between viral antibody titers and isolation of the EB virus.